scholarly journals Figure of Merit of One-dimensional Resonant Transmission Systems in the Quantum Regime

2009 ◽  
Vol 14 (1) ◽  
pp. 13-19
Author(s):  
Mustafa Ali Çipiloğlu ◽  
Sadi Turgut
1998 ◽  
Vol 545 ◽  
Author(s):  
X. Sun ◽  
Z. Zhang ◽  
G. Dresselhaus ◽  
M. S. Dresselhaus ◽  
J. Y. Ying ◽  
...  

AbstractBismuth as a semimetal is not a good thermoelectric material in bulk form because of the approximate cancellation between the electron and hole contributions. However, quantum confinement can be introduced by making Bi nanowires to move the lowest conduction subband edge up and the highest valence subband edge down to get a one-dimensional (1D) semiconductor at some critical wire diameter dc. A theoretical model based on the basic band structure of bulk Bi is developed to predict the dependence of these quantities on wire diameter and on the crystalline orientation of the bismuth nanowires. Numerical modeling is performed for trigonal, binary and bisectrix crystal orientations. By carefully tailoring the Bi wire diameter and carrier concentration, substantial enhancement in the thermoelectric figure of merit is expected for small nanowire diameters.


Optik ◽  
2016 ◽  
Vol 127 (5) ◽  
pp. 2620-2623
Author(s):  
Devendra Pal ◽  
Shikha Shukla ◽  
S. Prasad ◽  
Vivek Singh

2013 ◽  
Vol 743-744 ◽  
pp. 153-160
Author(s):  
Xiao Jie Hong ◽  
Xian Fan ◽  
Zhao Yang Wu ◽  
Guo Qiang Wang ◽  
Cheng Yi Zhu ◽  
...  

Microstructure engineering of thermoelectric materials can resolve the conflicts of electrical and thermal transports. Especially, one-dimensional structure can obviously improve the thermoelectric figure of merit because of its crystal anisotropy and strong quantum confinement effect. In this paper, the Te nanowires, one-dimensional core-shell heterostructure of Te/Bi and Te/Bi2Te3 were controlled synthesized by microwave assisted chemical synthesis. The effect of PVP concentration and reductant dropping rate on the microstructure of the Te nanowires were investigated. The experimental results showed that with increasing the amount of PVP, the Te nanowires got less crystallinity and its surface become more rough due to its steric hindrance effect. With decreasing reductant dropping rate, the longer and thiner Te nanowires were obtained. Epitaxial growth can describe the relation of core Te and shell Bi (or Bi2Te3). It has been found that Bi shell uniformly surrounded around Te nanowires core, but Bi2Te3 sheets were perpendicular to the c-axis of Te nanowires. The different core-shell heterostructure structure can be obtained by adjusting reaction conditions and controlling diffusion kinetics of Te and Bi.


1999 ◽  
Vol 23 (7) ◽  
pp. 1861-1866 ◽  
Author(s):  
M. Inoue ◽  
K. I. Arai ◽  
M. Abe ◽  
T. Fujii ◽  
S. Fan S. Fan ◽  
...  

2011 ◽  
Vol 44 (2) ◽  
pp. 295-298 ◽  
Author(s):  
K. H. Andersen ◽  
P. M. Bentley ◽  
L. D. Cussen

This article addresses the question of the most effective detector configuration for neutron spectrometers using a discussion of a particular case – constant-wavelength powder diffractometers at continuous neutron sources. A first variation uses an essentially one-dimensional `banana' detector coupled with out-of-scattering-plane beam divergence before and after the sample. A second variation uses an incident beam tightly defined both in- and out-of-plane coupled to a `4π' detector covering all possible scattering angles after the sample. It is widely believed that the 4π arrangement is superior for most varieties of neutron spectrometer but is more difficult and more expensive to implement. Starting from a commonly used overall instrument figure-of-merit, this article presents simple arguments leading to the surprising conclusion that this is untrue for these constant-wavelength powder diffractometers, provided only that the cylindrical samples used with the banana detector have a height greater than 2.4 times their diameter.


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